It does not surprise me. Any pilot that flys international routes over water would just for the hell of it see if he could land in an emergency on an unfamiliar airport. He might have been testing himself to see if he could put a 777 down on a 1,000 meter (little over 3,000’ runway)which would be an amazing feat. One he could land on but never take off from.
Or more obviously (can’t believe someone else hasn’t said this yet) perhaps the island was a refueling stop.
Certainly a possibility, however if this is information that was recovered from deleted data, it certainly looks suspicious given the circumstances.